Brightness: add support for Windows

src/detection/brightness/brightness_windows.cpp

@@ -0,0 +1,27 @@
+extern "C"
+{
+#include "brightness.h"
+}
+#include "util/windows/wmi.hpp"
+
+extern "C"
+const char* ffDetectBrightness(FFlist* result)
+{
+    FFWmiQuery query(L"SELECT CurrentBrightness, InstanceName FROM WmiMonitorBrightness WHERE Active = true", nullptr, FFWmiNamespace::WMI);
+    if(!query)
+        return "Query WMI service failed";
+
+    while(FFWmiRecord record = query.next())
+    {
+        FFBrightnessResult* display = (FFBrightnessResult*) ffListAdd(result);
+        ffStrbufInit(&display->name);
+        record.getString(L"InstanceName", &display->name);
+        ffStrbufSubstrAfterFirstC(&display->name, '\\');
+        ffStrbufSubstrBeforeFirstC(&display->name, '\\');
+
+        uint64_t brightness;
+        record.getUnsigned(L"CurrentBrightness", &brightness);
+        display->value = (float) brightness;
+    }
+    return NULL;
+}